The document discusses principles for designing workplaces and arranging components in workspaces based on anthropometric and ergonomic considerations. It covers topics such as workplace design based on static and dynamic body measurements, principles for seating and work surface design, and guidelines for arranging components based on importance, frequency of use, and functional relationships. The overall goal is to design workplaces and arrange components in a way that is comfortable, efficient and minimizes fatigue and risk of injury for users.

1. Workplace Design
By: Gaurav Singh Rajput
@gauravkrsrajput

2. WORKPLACE DESIGN
ANTHROPOMETRY
•Anthropometry deals with the measurement of
the dimensions and certain other physical
characteristics of the body such as volumes,
centers of gravity, inertial properties, and
masses of body segments.
•There are two primary types of body
measurement: static and dynamic (functional).
What is sometimes called engineering
anthropometry is concerned with the application
of both types of data to the design of the things
people use

3. Static Dimensions
• Static dimensions are measurements taken
when the body is in a fixed (static) position.
• They consist of skeletal dimensions (between
the centers of joints, such as between the
elbow and the wrist) or of contour dimensions
(skin surface dimensions such as head
circumference).

4. Dynamic (Functional) Dimensions
• These dimensions are taken under conditions
in which the body is engaged in some physical
activity.
• In most physical activities (whether one is
operating a steering wheel, assembling a
mousetrap, or reaching across the table for
the salt) the individual body members
function decide the dynamic dimensions.

5. Conversion….
 Although there is no systematic procedure for
translating static anthropometric data into dynamic
measurements, Kroemer (1983) offers the following
rules of thumb that may be helpful:
• Heights (stature, eye, shoulder, hip): reduce by 3
percent.
• Elbow height: no change, or increase by up to 5
percent if elevated at work.
• Knee height, sitting: no change, except with high-
heel shoes.
• Forward and lateral reaches: decrease by 30 percent
for convenience, increase by 20 percent for extensive
shoulder and trunk motions.

6. Principles in the Application of
Anthropometric Data
• Design for Extreme Individuals: In designing certain
features of our built physical world, one should try
to accommodate all (or virtually all) the population
in question.
• In some circumstances a specific design dimension
or feature is a limiting factor that might restrict the
use of the facility for some people; that limiting
factor can dictate either a maximum or minimum
value of the population variable or characteristic in
question.

7. Principles in the Application of
Anthropometric Data
• Designing for Adjustable Range: Certain features of
equipment or facilities can be designed so they can
be adjusted to the individuals who use them.
• Some examples are automobile seats, office chairs,
desk heights, and footrests. In the
• Design of such equipment, it frequently is the
practice to provide for adjustments to cover the
range from the 5th percentile female to the 95th
percentile male of the relevant population
characteristic (sitting height, arm reach, etc.).

8. Principles in the Application of
Anthropometric Data
• Designing for the Average: First of all, there is
no "average" individual. A person may be
average on one or two body dimensions, but
because there are no perfect correlations it is
virtually impossible to find anyone who is
average on more than a few dimensions.
• Often designers design for the average as a cop-
out so that they do not have to deal with the
complexity of anthropometric data.
• Designing for the average should only be done
after careful consideration of the situation and
never as an easy way out.

9. Using anthropometric data in design
1. Determine the body dimensions important in the design (e.g . Sitting
height as a basic factor in seat-to-roof dimensions in automobiles].
2. Define the population to use the equipment or facilities. This establishes
the dimensional range that needs to be considered (e.g., Children,
women, U.S. civilians, different age groups, world populations, different
races).
3. Determine what principle should be applied (e.g., design for extreme
individuals, for an adjustable range, or for the average).
4. When relevant, select the percentage of the population to be
accommodated (for example, 90 percent, 95 percent) or whatever is
relevant to the problem.
5. Locate anthropometric tables appropriate for the population, and
extract relevant values.
6. If special clothing is to be worn, add appropriate allowances (some of
which are available in the anthropometric literature).
7. Build a full-scale mock-up of the equipment or facility being designed
and using the mock-up, have people representative of large and small
users walk through representative tasks. All the anthropometric data in
the world cannot substitute for a full-scale mock-up .

10. Work spaces
• Work-space envelopes consist of the three-dimensional
spaces that are reasonably optimum for seated or
standing persons who perform some type of manual
activity.
• Thus (for example) control devices and other objects to
be used usually should be located within such space.
The reasonable limits of such space are determined by
functional arm reach, which is influenced by such
variables as direction of arm reach, the nature of the
manual activity, the use of restraints, apparel worn, the
angle of the backrest, and personal variables such as
age, sex, ethnic group, and handicaps.

11. Work spaces
• Whenever feasible, such spaces should be designed
with consideration for the personal characteristics of
the population to use the facility.
• It is fairly standard practice to design such space for
the 5th percentile of the using population, thus
making it suitable for 95 percent of the population.
• Thus, with such special populations the design of the
work space requires particular (and sometimes
individual) attention.

12. Work-Space Envelopes for Seated Personnel
• The limits of the work-space envelope for
seated personnel are determined by functional
arm reach, which in turn is influenced especially
by the direction of arm reach and the nature
of the manual activity (i.e., the task or function)
to be performed.
• Functional arm reach is also influenced by such
factors as the presence of any restraints and by
the apparel worn.
• Some examples of the effects of these variables
are given for illustration.

13. Work-Space Envelopes for Seated Personnel

14. Work-Space Envelopes for Standing Personnel

15. DESIGN OF WORK SURFACES
• Horizontal Work Surface Area: The horizontal work
surface area to be used by seated and "sit-stand" workers
generally should provide for manual activities to be
within convenient arm's reach.
• Certain normal and maximum areas were proposed by
Barnes (1963) and Farley (1955) and have been used
rather widely.
1. Normal area - This is the area that can be conveniently
reached with a sweep of the forearm while the upper
arm hangs in a natural position at the side.
2. Maximum area - This is the area that could be reached by
extending the arm from the shoulder.

16. Normal and maximum working area

17. Horizontal and slanting work surface
• Although most office activities such as reading and writing
are carried out on horizontal surfaces such as desks and
tables, Eastman and Kamon (1976) propose that (where
feasible) a slanted surface be used. In their study they
found that subjects using slanted surfaces (12° and 24°) had
better posture, showed less trunk movement, and reported
less fatigue and less discomfort than when using horizontal
surfaces.
• Bridger (1988) found similar results, as depicted in Figure
13-12. When using a slanted surface (ISO) subjects sat with
less bending of the neck, a more upright trunk, and less
trunk flexion than when using a horizontal work surface.
• The evidence seems clear that using slanted work surfaces
for visual tasks, such as reading, offers considerable
advantages in terms of posture over traditional horizontal
work surfaces.

18. Horizontal and slanting work surface

19. Work-Surface Height: Seated
• If a work surface is too low, the back may be bent over too far; and if
it is too high, the shoulders must be raised above their relaxed
posture, thus triggering shoulder and neck discomfort.
• When discussing work-surface height some confusion may be
introduced if a distinction is not made between work-surface height
and working height.
• Work surface height is simply the height of the upper surface of a
table, bench, desk, counter, etc. measured from the floor.
• Even this simple notion becomes a little complex when slanted work
surfaces are referred to; usually the height of the front edge and the
angle of the surface are specified.
• Working height; however, depends on what one is working on.
• When writing on paper, the working height is the same as the work-
surface height.
• When using a-keyboard (typewriter or computer) the working height
is taken as the height of the home row of keys (the "asdfghjkl" row on
a standard keyboard).
• When washing vegetables in a sink, the working height is actually
below the work-surface height.

20. General Principles for Seated Work Surfaces
• There are a few general principles related to
work-surface heights
1. If at all possible the work-surface height
should be adjustable to fit individual physical
dimensions and preferences.
2. The work surface should be at a level that
places the working height at elbow height.
3. The work surface should provide adequate
clearance for a person's thighs under the work
surface.

21. Seated Work-Surface Height and Arm Posture
• In recent years some investigators have recommended
reducing work-surface heights, generally to permit relaxed
postures of the upper arms with respect to working height.
• Working with relaxed upper arms and elbows at about 90°
provides comfort and helps maintain straight wrists, which
can be beneficial when performing repetitive tasks such as
typing or electronic assembly.
• On the basis of a European survey, Bex (1971) reports that
the most common heights of desks have, in fact, been
reduced from about 30 in (76 cm) in 1958 to about 28.5 in
(72 cm) in 1970.
• Based on his own and other anthropometric data, he
argues for a further reduction of fixed desk heights to
about 27 in (68.6 cm).

22. Seated Work-Surface Height and Thigh Clearance
• Work-surface height is also influenced by seat height,
the thickness of the work surface, and the thickness of
the thighs.
• The clearance between the seat and the underside of
the work surface should accommodate the thighs of the
largest user.
• ANSI (Human Factors Society, 1988) recommends 26.2
in (66.5 cm) as the minimum height for the underside of
a non adjustable seated work surface.
• With adjustable-height work surfaces, small users can
adjust the height so that the working height is at elbow
height with their feet on the floor.

23. Seated Work-Surface Height and Thigh Clearance
• ANSI (Human Factors Society, 1988) recommends
a range of height adjustments for the underside
of the work surface of 20.2 to 26.2 in (51.3 to
66.5 cm).
• This works fine unless the work surface is
unusually thick or the object being worked on is
large in the vertical dimension.
• When the work surface cannot be lowered
sufficiently for proper arm posture and thigh
clearance, a thinner work surface should be
considered.

24. Seated Work Surface Height and Nature of the Task

25. Work-Surface Height: Standing
• The critical features for determining work-surface heights
for standing workers are in part the same as for seated
workers, i.e., elbow height and the type of
work being performed.
• Figure 13-13 shows recommended heights for precision
work, light work, and heavy work as related to elbow
height (Grandjean , 1988).
• For light and heavy work the recommended work-surface
heights are below elbow height, whereas that for
precision work is slightly above (generally to
provide elbow support for precise manual control).
• We recommend, however, that precision tasks be
performed sitting down.

26. Work-Surface Height: Standing

27. General Principles of Seat Design
• Promote Lumbar Lordosis - When standing erect, the lumbar
portion of the spine (the small of the back just above the
buttocks) is naturally curved inward (concave), that is, it is
lordotic. Natural lumbar lordosis aligns the vertebrae of
the spine in a near vertical axis through the thigh and pelvis, as
shown in Figure 13-15.
• However, when one is sitting with the thighs at 90°, the lumbar
region of the back flattens out-and may even assume an outward
bend (convex), that is, it becomes kyphotic. as shown in Figure
13-15.
• This occurs because the hip joint rotates only about 60°, forcing
the pelvis to rotate backward about 30° to achieve the 90° thigh
angle. Lumbar kyphosis results in increased pressure on the discs
located 'between the vertebrae of the spine.

28. General Principles of Seat Design

29. Minimize Disc Pressure
• The discs between the vertebrae can be damaged by
excessive pressure. Unsupported sitting, i.e., not using a
backrest, increases disc pressure considerably over that
experienced while standing.
• Nachemson and Elfstrom (1970), for example. found that
unsupported sitting in an upright, erect posture (forced
lordosis) resulted in a 40 percent increase in
pressure compared to standing.
• Unsupported sitting in a forward slumped posture
increased pressure 90 percent compared to standing.

30. Minimize Static Loading of the Back Muscles
• Andersson (1987) reports that muscular activity as
measured by electromyography (EMG) is similar when
standing or sitting. In fact;-EMG -activity-decreases when
sitting in a forward slumped posture, even though, as
discussed above, this posture produces maximum
pressure on the discs.
• There are ways, however, to relax the muscles without
sacrificing the discs. Andersson and Ortengren (1974)
found a reduction in muscular activity in the back when
the backrest was reclinedup to 110⁰ beyond which little
additional relaxation was found.
• The effects of a lumbar support on EMG activity have
been mixed (Andersson; 1987).

31. Reduce Postural Fixity
• Grieco (1986) discusses the problem of postural fixity,
that is, sitting in one position for long periods without
significant postural movement.
• This is especially common when using a computer where
the hands remain on the keyboard and the eyes are fixed
on the screen. The human body is simply not made to sit
in one position for long periods of time. The discs
between the vertebrae depend on changes in pressure to
receive nutrients and remove waste products.
• Discs have no blood supply; fluids are exchanged by
osmotic pressure. Sitting in one posture-no matter how
good it is-will result in reduced nutritional exchanges and
in the long term may promote degenerative
processes in the discs.

32. Provide for Easy Adjustability
• Adjustable furniture is fundamental to good human factors
design. Studies have shown that providing adjustable seats
increases productivity (Springer, 1982) and reduces
complaints of shoulder and back pain (Shute and Starr, 1984).
• The problem is that workers are usually not aware of the
adjustability features available on their chairs and rarely use
the ones they know about. In a survey of 2000 air traffic
controllers it was found that only about 10 percent adjusted
their seats during the day and more than half were not even
aware of some of the adjustments that were available. The
personal experience of one of your authors confirms this
among newspaper employees. One feels like a hero when
showing someone how to adjust their backrest angle or
backrest height to achieve a more comfortable posture.

33. ARRANGING COMPONENTS IN WORKSPACE
• Ideally, we would like to place each component in an optimum
location for serving its purpose.
• This optimum would be predicated on human capabilities and
characteristics, including sensory capabilities and
anthropometric and biomechanical characteristics.
• The optimum location would facilitate performance of the
activities carried out in the space.
• Unfortunately, it is usually not possible to place each
component in its optimum location.
• Placing a control in the optimum location for fast response
may separate it from the display to which it is related.
• To bring order to such potential chaos requires setting
priorities and making trade-offs.

34. PRINCIPLES OF ARRANGING
COMPONENTS IN WORKSPACE
Importance Principle:
• This principle states that important components
be placed in convenient locations.
• Importance refers to the degree to which the
component is vital to the achievement of the
objectives of the system.
• The determination of importance usually is a
matter of judgment made by people who are
experts in the operation of the system.

35. PRINCIPLES OF ARRANGING
COMPONENTS IN WORKSPACE
Frequency-of-Use Principle:
• This principle states that frequently used
components be placed in convenient
locations.
• For example, the activation control of a punch
press should be conveniently located because
it is used very frequently.
• A copying machine should be near a typist.

36. PRINCIPLES OF ARRANGING
COMPONENTS IN WORKSPACE
Functional Principle:
• The functional principle of arrangement provides for the
grouping of components according to their function, such
as the grouping of displays, controls, or
machines that are functionally related in the operation of
the system.
• Thus, temperature indicators and temperature controls
might well be grouped
• Electric power distribution instruments and controls
usually should be in the same general location.

37. PRINCIPLES OF ARRANGING
COMPONENTS IN WORKSPACE
Sequence-of-Use Principle:
• In the use of certain items, sequences or
patterns of relationship frequently occur in
the operation of equipment or in performing
some service or task.
• The items would be so arranged as to take
advantage of such patterns.

38. PRINCIPLES OF ARRANGING
COMPONENTS IN WORKSPACE
• In putting together the various components of a
system, no single guideline can, or should, be applied
consistently across all situations.
• But in a very general way, and in addition to the
optimum premise, the notions of importance
and frequency probably are particularly applicable to
the more basic phase of locating components in a
general area in the work space
• The sequence of use and functional principles tend
to apply more to the arrangement of
components within a general area.

39. Time vs Principles of control

40. Types of Data for Use in Arranging
Components
1. Basic data about human beings - Anthropometric and
biomechanical data are especially relevant, but other
types of data may also be useful, such as data on sensory,
cognitive, and psychomotor skills. Such data generally
come from research undertakings and are published in
various source books.
2. Task analysis data - These are data about the work
activities of people who are (or would be) involved in the
specific system or work situation in question.
3. Environmental data - This category covers any relevant
environmental features of the situation, such as
illumination, noise, vibration, motion, heat, traffic and
congestion, etc.

41. Links
• Relationships between components, be they people or things,
are called links.
• Types of Links - communication links, control links, and
movement links.
• Communication and control links can be considered as
functional.
• Movement links generally reflect sequential movements
from one component to another.
• Some versions of the three types of links are
1. Communication links
a. Visual (person to person or equipment to person)
b. Auditory, voice (person to person. person to
equipment. or equipment to person)
c . Auditory. Non voice (equipment to person)
d. Touch (person to person or person to equipment)

42. Links
2. Control links
a. Control (person to equipment)
3. Movement links (movements from one
location to another)
a. Eye movements
b. Manual movements, foot movements or
both
c. Body movements

43. GENERAL LOCATION OF CONTROLS AND
DISPLAYS WITHIN WORK SPACE
• It is reasonable to assume that any given component
in a system or facility would have some reasonably
optimum location, predicated
on whatever sensory, anthropometric,
biomechanical, or other considerations are relevant.
• Although the optimum locations of some specific
components probably would depend on situational
factors, some generalizations can be
made about certain classes of components.

44. Visual Displays
• The normal line of sight is usually considered to
be about 15° below the horizon.
• Visual sensitivity accompanied by moderate eye
and head movements permits fairly convenient
visual scanning of an area around the normal line
of sight.
• The area for most convenient visual regard (and
therefore generally preferred for visual displays)
has generally been considered to be defined by a
circle roughly 10° to 15° in radius around the
normal line of sight.
• There are indications that the area of most
effective visual regard is not a circle around the
line of sight but rather is more oval.

45. Visual Displays

46. Hand Controls
• The optimum location of hand control devices is, of
course, a function of the type of control, the mode of
operation, and the appropriate criterion of
performance (accuracy, speed, force, etc.).
• Controls That Require Force – Figure shows the
serious reduction in effective force as the arm is
flexed when
it is pulled toward the body.
• The maximum force that can be exerted by putting is
about 57 to 66 cm forward from the seat reference
point, and this span, of course, defines the optimum
location of a lever control (such as a hand brake) if the
pulling force is to be reasonably high.

47. Controls That Require Force

48. Controls on Panels
• Many controls are positioned on panels or in
areas forward of the person who is to use
them.
• Because of the anthropometric and
biomechanical characteristics of people,
controls in certain locations can be operated
more effectively than those in other locations.

49. Controls on Panels

50. Two hand controls
• Some operations require the simultaneous use
of controls by both hands. For example, in the
operation of some metal-forming presses, the
operators have to press two push buttons-for
safety reasons to keep the hands away from the
press when it is activated.
• In some instances these push buttons ("palm"
buttons operated by the palm of the hand) are
at eye level. This location was suspected of
being responsible for a high rate of muscular
strain and sprain Injuries.

51. Foot Controls
• Foot controls generally need to be located in fairly
conventional areas; such as those depicted in Figure. These
areas, differentiated as optimal
• and maximal, for toe-operated and heel-operated controls,
have been delineated on the basis of dynamic
anthropometric data.
• The maximum areas indicated require a fair amount of
thigh or leg movement or both and preferably they should
be avoided as locations for frequent or continual pedal use.
Incidentally, Figure is predicated on the use of a horizontal
seat pan; with an angular seat pan (and an angled backrest)
the pedal locations need to be manipulated accordingly.
• Figure generally apply to foot controls that do not require
substantial force.

52. Foot Controls

53. Mirror-Image Arrangements
• In some process control and nuclear power plants two
control panels with identical controls and displays may
exist in the same facility. For example, some nuclear
power plants have two reactors, each with its own set of
control panels. Some machines have controls on two
sides so the operator can work from either side.
• Mean response times with the non mirror-imaged
arrangement were faster than with the mirror-imaged
panel, especially during the early trial blocks.
• The difference between mirror- and non mirror-imaged
configurations grew smaller as subjects continued to
practice and became more accustomed to the mirror
imaged panel.

54. SPACING OF CONTROL DEVICES
• Inadvertent "touching errors" in the use of knobs of
various diameters as a function of the distances
between their edges were examined. In this
instance the errors dropped sharply with increasing
distances between knobs up to about I in (2.5 cm),
while beyond that distance performance improved
at a much slower rate. When separate comparisons
were made between knob centers (rather than
edges), however, performance was more nearly
error-free for knobs of 1/2-in (1.2 cm) diameter
than for the larger knobs.

55. GENERAL GUIDELINES IN DESIGNING
INDIVIDUAL WORKPLACES
• In designing workplaces some compromises are almost
inevitable because of competing priorities. In this regard,
however, appropriate link values can aid in the trade-off process.
• First priority: Primary visual tasks
• Second priority: Primary controls that interact with primary visual
tasks
• Third priority: Control-display relationships - (put controls-near
associated displays, compatible movement relationships, etc.)
• Fourth priority: Arrangement of elements to be used in sequence
• Fifth priority: Convenient location of elements that are used
frequently
• Sixth priority: Consistency with other layouts within the system or
in other systems